How to Encrypt Text Messages & DM Securely in 2018

Short message service started operating commercially in the early ‘90s and usage soared. Today, another form of messaging is taking a piece of the user base — instant messaging using smartphone apps, such as WhatsApp, which has 1.5 billion users, and Facebook Messenger, which was 1.3 billion.

Such numbers are not surprising. Messaging apps let you reach somebody halfway across the world instantly. You can send texts, as well as pictures, audio and video. They are easy to install on smartphone operating systems and some are available for computer operating systems.

We all know we need to protect our passwords, avoid suspicious websites and use antivirus and antimalware software, but, in today’s shifting landscape, guarding our privacy is paramount. With government programs such as PRISM and U.S. agencies reading your data, even your texts might not be safe, so we’re going to show you how to encrypt text messages.

There’s nothing to fear if you’re not inclined to do unnecessary software-related work. We’re going to give you a list of apps that already encrypt your messages before transmitting or require minimal work. Next, we’ll show you how to encrypt your SMS messages if you want to do that. For even better mobile security, we suggest using a VPN for mobile, as well.

Best Secure Messaging Apps

To begin sending encrypted messages, you’ll need an app that can do it. Those on our list take similar approaches to security and privacy. The encryption protocols work in the background, enabling you to focus on your messages, so that’s basically the same as sending an ordinary text message. With that out of the way, let’s take a look at them.

Like the rest of the apps on this list, Signal is available for Android, iOS, Windows, Mac and Debian-based Linux systems. There’s also a Chrome extension. Since it’s open-source, anyone can look at its source code, meaning security experts can analyze it for vulnerabilities. It’s the best choice for privacy, according to journalists and other experts, including Edward Snowden.

Open Whisper Systems explains on its website: “Signal is made for you. As an Open Source project supported by grants and donations, Signal can put users first. There are no ads, no affiliate marketers, no creepy tracking. Just open technology for a fast, simple, and secure messaging experience. The way it should be.“

Since it is funded that way, you can, presumably, trust it more than app companies that are dying to get your information to sell you ads.

Signal’s privacy is secured with end-to-end encryption, which means the contents of the chat aren’t visible to anyone but the parties in the conversation. Calls are also encrypted, so no one can listen in. The app uses the Signal protocol, which Open Whisper Systems developed in 2013.

The only information it can produce is the date and time a user registered with Signal and the last date the user connected.

You can also set your encrypted messages to disappear after a period of time. If you do, they will do so for all parties in the conversation.

We’re going to use Signal for our example of how to set up an app for private messaging:

Step 1: Get the Signal app from Google Play Store or iPhone App Store. Whichever you use, the procedure will be similar. You’ll have to tap “accept” to give Signal the privileges it needs to function.

While you will share your contacts with Signal, its servers only mine the data for for contacts that use it. Afterward, it deletes the data, so no one can get it.

Step 2: The app needs your phone number to register and verify your account. Verification happens automatically when you get an SMS message with a code.

You can give Signal access to the SMS to read the code and allow it to send SMS messages.

Step 3: Signal will ask you if you want to set it as your default messaging app.

You can send your text to anyone, but if they’re not using Signal, it will remain unencrypted. Signal will tell you it’s an “unsecured SMS” when that happens.

You’ll have to invite the person you want to contact to use Signal before you can send an encrypted message.

Step 4: To send an encrypted message, tap the pencil in the lower right-hand corner and choose a Signal user. You’ll see “send Signal message,” which indicates that it is encrypted. Voilà, that’s all it takes to use encrypted messaging.

You might have noticed that the list of contacts you can invite to use Signal is much longer than the list of those who already use it. That’s because not a lot of people do, which is one of its biggest drawbacks.

Usability is another important factor to consider, and it’s something the next app on our list offers.

That said, WhatsApp uses end-to-end encryption by default — Signal’s protocol, in fact — but doesn’t encrypt metadata with it. Facebook isn’t sitting around, either, as WhatsApp rolled out a timely patch that prevented the use of an exploit.

That metadata shows how you use the application. WhatsApp is available for Android, iPhone, Mac and Windows.

Telegram is a cloud-based, meaning you can access your messages from various devices and keep data in the cloud. It lets you send encrypted messages, files and participate in real-time chat with groups of up to 100,000 members. The app is mostly open source and the company reveals the most important parts of its encryption, called mtProto.

To use end-to-end encryption, you’ll have to use a secret chat. “Secret chats are meant for people who want more secrecy than the average fella,” says the FAQ on Telegram’s website. Secret chats also let you set your messages to self-destruct after a set time and are device-specific, meaning you can’t access them from the device of origin.

Threema goes beyond the standard features, such as end-to-end encryption, voice calls and messages. You can use Threema anonymously since it doesn’t require you to supply your phone number or email address. Instead, you get a random, eight-digit Threema ID when you start the app for the first time.

That’s one part of your identity. The second is a key pair — a public key and a private key that is necessary for encryption. When someone sends you a message, they encrypt it using your public key. Only your private key, which remains on your device, can decrypt it. You don’t even need to give it access to your address book to use the app.

It helps that Threema and its servers are based in Switzerland, which has some of the best privacy laws. Parts of the app, including its encryption library, are open source. To enjoy its benefits, you’ll have to purchase Threema for $2.99. It’s available for Android, iOS and Windows Phone.

The Snowden-endorsed alternative to Signal, Wire, lets register with an email instead of your phone number. It also provides end-to-end encryption. Since it’s based in Europe — the company is in Switzerland, with servers in Ireland and Germany — it’s under the jurisdiction of privacy laws there, particularly the General Data Protection Regulation.

It works on all major platforms and browsers, and its Personal plan is free. The Pro subscription targets businesses by providing audio and video conferences as well as full admin controls. It costs $4.60 per user per month.

The only thing the company can provide authorities is the date of account creation, the date of last use, number of messages sent or received and the type of device used to create the account.

Note that Wickr is based in the U.S. and under the jurisdiction of laws that govern there. Users that live in Europe can opt out of the transfer of their personal data, though, which is convenient. That said, some features of Wickr might not work if you do that. Wickr is open source, so check out the code for yourself on GitHub.

Wickr Me is for personal users and won’t cost you a dime. Wickr pro costs $25 per user per month and is suitable for teams because it comes with many collaboration features. For organizations, Wickr Enterprise will do the trick. You’ll need to contact the company for an estimate. Check out its comparison chart to see which works for you.

The SMS Alternative

We’ve covered using apps that send messages via the internet, but you might want to send a message while you don’t have data on your plan or access to WiFi. Plain old SMS will get the job done, but you’ll have to encrypt it first. You can do that with an aptly named app: Encrypted SMS.

The app uses “state of the art algorithms” — the ECDH algorithm for key agreement and an AES/CBC/PKCS5P adding with 256 bits key algorithm to encrypt and decrypt all messages — that guarantee the privacy and security of your messages. The encryption system revolves around public and private encryption keys, which is a sure way to handle it.

To send messages, the person you’re trying to text needs to have Encrypted SMS installed. Then, you’ll need to exchange public keys to set up an encrypted SMS channel.

You can get access to additional features, though the app doesn’t specify what they are, for $1.87.

Final Thoughts

Protecting your privacy isn’t a trivial matter, especially if you’re not just chatting about cats and viral videos. Governments are always trying to get your data under the guise of increasing security. That’s a fine line and it’s easy to cross. What you can do is take matters into your own hands and protect your information the best you can.

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The apps we’ve mentioned will help you do that. Signal is in the spotlight, but it requires your phone number and has few users. That might be unacceptable to some, which is why other apps, such as Threema, Wickr and Wire, are on the list. Some are also suitable for multiple users. If you want to use SMS, we’ve got that covered with Encrypted SMS.

How do you feel about privacy? Are you going to switch to a more secure texting app or are you going to stick with WhatsApp, Facebook Messenger or plain SMS? Let us know in the comments below. Thank you for reading.

Branko Vlajin

Branko has a bachelor’s degree in software engineering and likes to write cloud storage, backup and privacy laws. Naturally, he thinks Assange and Snowden are champions of the internet age. In his spare time, he does all sorts of stuff, including photography, reading, salsa dancing and learning languages. He also likes barbecue, hiking, traveling and skiing. Favorite movie never made: Jodorowsky’s Dune.